As the tsoureki I bought for Easter left in the fridge only half-eaten, I made French-toast with tsoureki. French toast made with brioche is excellent, so tsoureki should work well, I thought.
It, indeed, was very good. The texture is lovelier than normal French toast. By inference, if I make bread and butter pudding from tsoureki, it should be good, too.
A good idea to use up left-over tsoureki!